This invention relates generally to ball bearing cages and, more particularly, to one-piece ball bearing cages that are installed in a ball bearing assembly by "popping" or "snapping" over bearing balls.
One common type of ball bearing cage comprises two halves joined together by welding, riveting or mechanical interlock. These two-piece ball bearing cages require insertion of the two halves from opposite ends of the ball bearing after the bearing balls have been loaded between the bearing rings. Welding is difficult due to potential arcing through the bearing balls, and riveting is difficult due to the many small rivets that must be inserted. Additional cost results from inspection and rejection of defective bearing assemblies.
Additional problems are associated with two-piece ball bearing cages due to space requirements. Such ball bearing cages require sufficient circumferential distance between bearing balls to permit welding, riveting or mechanical interlock of the two halves. As a result, fewer bearing balls may be inserted, reducing the load capacity of the bearing assembly. Also, when multiple rows of bearing balls are used, the rows must be separated to provide space for the ball bearing cages, adding to the axial length of the bearing assembly.
Another type ball bearing cage comprises a sheet metal ring having an initial undulatory configuration with open ball pockets spaced apart by U-shaped connecting portions. After being inserted between the bearing rings, with bearing balls placed in the pockets, the U-shaped connecting portions are upset, causing the sides of the connecting portions to spread and conform to the contour of the bearing balls. However, forming the ball bearing cages directly against the bearing balls often results in excess gripping of the bearing balls or in insufficient ball retention.
Ball bearing cages may also employ a one-piece design having resilient fingers or lips which snap over the bearing balls as the bearing balls enter the ball pockets to provide a simple pop-in assembly. Such one-piece ball bearing cages are difficult to form of metal with sufficient ball contacting surface to retain the bearing balls. Molded polymer ball bearing cages of similar one-piece pop-in design may provide improved wrap-around and ball conformity. However, such polymer ball bearing cages are limited to low temperature and low strength applications.
The foregoing illustrates limitations known to exist in present ball bearing cages. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.